import java.util.Scanner;

public class Work_1 {
    public static void main(String[] args) {
        System.out.println("请输入圆的半径：");
        Scanner reader = new Scanner(System.in);
        double a = reader.nextDouble();
         CircularArea(a);
    }
    public static void CircularArea(double r) {
        double pi = 3.14;
        System.out.printf("圆的面积是%.2f", pi * r * r);
        System.out.printf("圆的面积是%.2f", 2 * pi * r);
    }



}
